The sensitization of young strain 13 guinea pigs with homologous spinal cord in complete Freund's adjuvant and killed mycobacterium tuberculosis has been shown to result in a relapsing and remitting disease in about 65% of the animals injected. Our recent results have shown that the IgG was significantly increased in CSF of animals sacrificed during the first remission, first relapse and late stages of the disease. The isoelectric focusing patterns of CSF and serum from relapsing EAE animals, showed oligoclonal IgG bands. Since these results are consistent with those observed in multiple sclerosis, we propose to study the specificity of the oligoclonal IgG using animals with chronic R-EAE and those injected with streptococcal antigen. Although the latter group did not develop EAE, their CSF showed presence of oligoclonal IgG bands. The specificity of the oligoclonal IgG to specific brain and bacterial antigens in the above animals will be determined by imprint electroimmunofixation method. It is anticipated that these studies will lead to a better understanding of the synthesis of oligoclonal band formation in multiple sclerosis.